031 Walbro WA-2 Pump Diaphragm Arrangement

[PogoInTheWoods]

Working on an 031 AV that has the Walbro WA-2 carb with what seems to be a fuel delivery issue. Came to me with a new carb kit so that's the first thing I checked. All looked good until I checked the IPL to see if there was supposed to be a diaphragm under the circuit plate (doesn't appear to be). Turns out there is supposed to be a second diaphragm on the pump side though..., at least according to the WA exploded illustration in Stihl's 031 IPL. It's also shown in the Walbro IPL for a WA carb. D-10 and K-10WAT are the kits. Happened to have a couple of each on hand. Out of all the diaphragms included in the kits, only one pump diaphragm in either kit will fit the pegs on the cover. What appears to be the second diaphragm (surge/suction diaphragm) has a slightly different hole alignment as do the other pump diaphragms and simply will not line up with the cover pegs.

Guess what I'm wondering is if the WA-2 is exclusive to the 031 and doesn't actually use the second pump side diaphragm or whether there's a Stihl kit that includes it..., or maybe a different Walbro kit. Here's what's in the 031 IPL. #19 would be the diaphragm in question.

TIA for any enlightenment.

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[Woodslasher]

19 is a spacer, not a diaphragm if I’m reading it right.

 

[PogoInTheWoods]

 

[Woodslasher]

Huh, now I'm stumped.

 

[HarleyT]

Are you using an OEM kit?

Does the old one fit? If so, why not just use that?

 

[PogoInTheWoods]

OEM Walbro kit which doesn't include a #19 with proper alignment hole spacings, just a gasket and pump diaphragm with the correct hole spacings for the WA-2 cover. None of the other diaphragms or the other pump side gasket in the kits fit the peg spacings of the cover. Kinda leaning toward the Stihl IPL simply being a copy of a basic WA carb and the WA-2 used on the 031 doesn't actually use the extra diaphragm even though it's listed (and numbered) in the 031 IPL.

Wasn't one in the carb when I got the saw. Just the normal pump diaphragm.

 

[HarleyT]

#0000 007 1063 ?

 

[HarleyT]

https://walbro.force.com/parts/Comm_PartsServiceDetails?partId=a0Fo000000V5CFOEA3

Not listed...

 

[PogoInTheWoods]

Saw that too.

 

[PogoInTheWoods]

Also listed as NLA (as is the cover) in MediaCat.

 

[PogoInTheWoods]

0000 007 1063

What's that?

 

[HarleyT]

See if this blows up a tad.

 

[HarleyT]

Stihl's kit.

 

[HarleyT]

Here is one on E-Bay.

 

[PogoInTheWoods]

Looks like the right diaphragm and the right kit. Where'd you come up with that part number?

 

[PogoInTheWoods]

Top is a WA-2 gasket and diaphragm. Bottom is another WA* gasket and diaphragm from the same WAT kit. Notice the obvious different peg hole sizes/spacings between the two. No suction chamber diaphragm included in any of the WAT kits I've checked.

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[PogoInTheWoods]

Here's the supplemental kit referenced in MediaCat.

https://www.ebay.com/i/262918512256...MsL6LC5sAwvpiq3uTqrsYbzjVS0ujNNxoCK_YQAvD_BwE

 

[HarleyT]

Always keep old price books....

 

[PogoInTheWoods]

Cool. MediaCat doesn't list a carb kit as you may have already discovered -- just that 1114-007-1005 diaphragm/gasket set. Odd that Walbro includes everything else except that one diaphragm in both the D-10 and K-10 WAT kits.

 

[PogoInTheWoods]

Thanks for the input. 'Preciate it.